A wide variety of devices are known and are currently used in spontaneously breathing anaesthetized patients, during recovering after anaesthetics, in weaning of a certain group of patients in intensive care, or during resuscitation to provide a clear and hands-free airway. A number of these devices are listed in the applicant's co-pending earlier application GB2,393,399A (Nasir), the text of which is hereby imported by reference and which is intended to form an integral part of this disclosure. GB2,393,399A describes a new type of airway device which has a soft laryngeal cuff adapted to fit anatomically over and form a seal with the laryngeal structure of a patient. An essential feature of certain embodiments of this device is a so-called buccal cavity stabiliser, located around the airway tube, and which is designed to nest with the anterior aspect of the patient's tongue.
The laryngeal cuffs on these devices are generally non-inflatable, but rather are formed from a soft, deformable material that can adapt to the individual detail of the patient's laryngeal inlet to form a satisfactory seal. It was precisely because of the very soft, deformable nature of these cuffs that it was considered necessary to incorporate some form of stabiliser to locate the cuff during insertion and to maintain a good gas-tight contact with the laryngeal inlet at all times during use. It should be borne in mind that “use” can involve the patient in many hours on the operating table under anaesthesia and can also involve use in accident and emergency situations involving hostile conditions that are non-ideal for such treatments.
It has now unexpectedly been discovered that a stabiliser, whilst still desirable, is not essential to achieve a good gas-tight seal between the cuff and the laryngeal inlet of the patient. Since a buccal cavity stabiliser adds both weight and cost there are positive advantages in eliminating this feature from the design. Weight and cost are both important features, particularly where the item is intended as a single use or disposable item.
It has also been deemed possible to reduce the material in the laryngeal cuff by manufacturing as a preformed/prefilled anatomical cuff, and by potentially removing the gastric channel.
It is an object of the present invention to provide an airway device that is both simple and effective to use and cost-effective to manufacture.
Where a single use item is concerned, cost of manufacture, and minimising this cost, is important. A further objective of the present invention is to provide cost-effective methods for manufacturing airway devices that enable the unit cost per item to be minimised.
It is also an object of this invention to satisfy the requirements of clinical situations where a buccal cavity stabiliser would not enhance, but impede the operation. For example in many opthamalogical, and maxillofacial or dental surgery the use of a reinforced tube are preferable, as the tube can flexibly moved to one side to continue to provide an airway for the patient, whilst not interfering with the operation. In summary, where it might be advantageous to have an airway device with a buccal cavity stabiliser in some applications, we have discovered that there are several applications where this is disadvantageous. In fact there are several applications where it is just not practical to have a buccal cavity stabiliser.